A man has shot dead two female police officers and a civilian in the eastern Belgian city of Liège.

The gunman also took a female cleaner hostage at a school before being killed by police. Four other police officers were also injured.

The man's motive is not yet clear but the incident is being treated as terrorism.

Police sources quoted in local media said the man was heard shouting "Allahu Akbar" ("God is greatest" in Arabic).

Belgian broadcaster RTBF said the gunman was let out from prison on temporary release on Monday where he had been serving time on drug offenses. It said that he may have been radicalized while in jail.